Question

What is the 7th term of the geometric sequence where a1 = 1,024 and a4 = -16?

Answer 1

well 1st the formula for a term in a geometric series is

\[a_{n} = a_{1} \times r^{n - 1}\]

1st you need to find the common ratio before finding the 7th term

so use what you know

\[-16 = 1024 \times r^{4 -1}\]

solve for r.


when you have it, go to the formula and find the 7th term with n = 7

Answer 2

r=-1/4?

Answer 3

thats correct... so

just evaluate

\[a_{7} = 1024 \times (\frac{-1}{4})^{7 -1}\]

Answer 4

you should get a positive answer

Answer 5

so it is .25

Answer 6

thats right

Answer 7

Thankyou that helped alot